Farm Engines and How to Run Them, by James H. Stephenson, Part 8

Good evening, and thank you for joining me for another Boring Books for Bedtime. I hope tonight's selection provides all the boredom your busy brain needs to quiet down and let you get some sleep. Before we begin, I'd like to give a special shout-out of thanks to some new members of our Patreon family. family, Jen, Brooke, and Tracy. Thank you all so much for supporting this podcast. By becoming members of Patreon, you help us remain 100% listener-supported and ad-free for everyone, and it's very much appreciated. If you're interested in supporting Boring Books for Bedtime and finding out more about the perks available to subscribers, including exclusive episodes, full books, and giveaways found nowhere else, you'll find a link to Patreon in the show description. You'll also find a link to BuyMeACoffee.com, where you can support us with a one-time tip, no subscription required. I hope you'll take a moment to check them out. Now, let's read and relax Find a comfortable spot Adjust your volume Take a nice deep breath in Let it out slowly And off we go Tonight, let's round out our theme month of long-time favorites with more from a book whose popularity has always come as a bit of a surprise to me. And yet, I so thoroughly enjoy reading it, I don't know why I'm surprised. Let's relax with more from Farm Engines and How to Run Them The Young Engineer's Guide A simple, practical handbook for experts as well as for amateurs, fully describing every part of an engine and boiler, giving full directions for the safe and economical management of both. Also several hundred questions and answers often given in examinations for an engineer's license And chapters on farm engine economy with special attention to traction and gasoline farm engines And a chapter on the science of successful threshing By James H. Stevenson and other expert engineers with numerous illustrations showing the different parts of a boiler and engine and nearly every make of traction engine with a brief description of the distinctive points in each make. First published in 1903 by Frederick J. Drake & Co. Chicago Let's pick up right where we left off, in the middle of Chapter 13, Gas and Gasoline Engines. Let's begin. Description of the Gas or Gasoline Engine The gas engine consists of a cylinder and piston, piston rod, crosshead, connecting rod, crank, and flywheel, very similar to those used in the steam engine. There is a gas valve, an exhaust valve, and in connection with the gas valve, a self-acting air valve. The gas valve and the exhaust valve are operated by lever arm or cam, worked from the main shaft, arranged by spiral gear or the like, so that it gets one movement for each two revolutions of the main shaft. Such an engine is called four-cycle, meaning one power stroke to each four strokes of the piston, and works as follows As the piston moves forward, the air and fuel valves are simultaneously opened and closed starting to open just as the piston starts forward, and closing just as the piston completes its forward stroke Gas and air are simultaneously sucked into the cylinder by this movement As the cylinder returns, it compresses the charge taken in during the forward stroke until it again reaches back center The mixture in the auto engine is compressed to about 70 pounds per square inch Ignition then takes place, causing the mixture to explode and giving the force from which the power is derived As the crank again reaches its forward center, the piston uncovers a port which allows the greater part of the burnt gases to escape As the piston comes back, the exhaust valve is opened, enabling the piston to sweep out the remainder of the burnt gases. By the time the crank is on the back center, the exhaust valve is closed and the engine is ready to take another charge, having completed two revolutions, or four strokes. The side shaft, which performs the functions of opening and closing the valves, getting its motion in the Columbus engine by a pair of spiral gears, makes but one revolution to two of the crankshaft. Gas engines are governed in various ways. One method is to attach a ball governor similar to the waters on the steam engine. When the speed is too high, the balls go out, and a valve is closed or partly closed, cutting off the fuel supply. Since the engine takes in fuel only once in four strokes, the governing cannot be so close as on the steam engine, since longer time must elapse before the governor can act. Another type of governor operates by opening the exhaust port and holding it open. The piston then merely draws in air through the exhaust port, but no gas. This is called the hit-or-miss governing type. One power stroke is missed completely. The heat caused by the explosion within the cylinder is very great. Some say as high as 3,000 degrees. Such a heat would soon destroy the oil used to lubricate the cylinder and make the piston cut, as well as destroying the piston packing. To keep this heat down, the cylinder is provided with a water jacket, and a current of water is kept circulating around it to cool it off. When gas is used, the gas is passed through a rubber bag, which helps to make the supply even. It is admitted to the engine by a valve similar to the throttle valve on an engine. Gasoline is turned on by a similar valve or throttle. It does not have to be gasified, but is sucked into the cylinder in the form of a spray. As soon as the engine is started, the high heat of the cylinder caused by the constant explosions readily turns the gasoline to gas as it enters. The supply tank of gasoline is placed outside the building or at a distance and stands at a point below the feed. A small pump pumps it up to a small box or feed tank, which has an overflow pipe to conduct any superfluous gasoline back to the supply tank. In the gasoline box or feed tank, a conical-shaped basin is filled with gasoline to a certain height, which can be regulated. Whatever this conical basin contains is sucked into the cylinder with the air By regulating the amount in the basin The supply of gasoline in the cylinder can be regulated to the amount required For any given amount of work In the Columbus engine This regulation is accomplished by screwing the overflow regulator up or down There are two methods of igniting the charge in the cylinder in order to explode it. One is by what is called a gasoline or gas torch. A hollow pin or pipe is fixed in the top of the cylinder. The upper part of this pin or pipe runs up into a gasoline or gas lamp of the Bunsen type, where it is heated red hot. When the gas and air in the cylinder are compressed by the backstroke of the piston, some of the mixture is forced up into this pipe or tube until it comes in contact with the heated portion and is exploded, together with the rest of the charge in the cylinder. Of course, this tube becomes filled with burnt gases, which must be compressed before the explosive mixture can reach the heated portion. And no explosion is theoretically possible until the piston causes compression to the full capacity of the cylinder. The length of the tube must therefore be nicely regulated to the requirements of the particular engine used. The other method is by an electric spark from a battery Two electrodes of platinum or some similar substance Are placed in the compression end of the cylinder The spark might be caused by bringing the electrodes sufficiently near together At just the right moment But the more practical and usual way is to break the current closing it sharply by means of a lever worked by the gearing at just the moment the piston is ready to return after compressing the charge. The electric spark is by long odds the most desirable method of ignition being safer and easier to take care of but it requires some knowledge of electricity and electric connection to keep it always in working order. Operation of Gas and Gasoline Engines To all intents and purposes, the operation of a gas or gasoline engine is the same as that of a steam engine, with the care of the boiler eliminated. The care of the engine itself is practically the same, though the bearings are relatively larger in a gasoline or gas engine and do not require adjustment so often. Some manufacturers will tell you that a gas engine requires no attention at all. Anyone who went on that theory would soon ruin his engine. To keep a gasoline engine in working order so as to get the best service from it and make it last as long as possible, you should give it the best of care. An engine of this kind needs just as much oiling and cleaning as a steam engine. All bearings must be lubricated and kept free from dirt. Great care must be taken that the piston and cylinder are well lubricated. In addition, the engineer must see that the valves all work perfectly tight, and when they leak in any way, they must be taken out and cleaned. Usually the valve seats are cast separate from the cylinder so that they can be removed and ground when they have worn Also, the water jacket must be kept in order so that the cylinder cannot become too hot. Starting a gasoline engine It is something of a trick to get a gasoline or gas engine started, especially a gasoline engine. and some skill must be developed in this or there will be trouble. This arises from the fact that when an engine has not been running, the cylinder is cold and does not readily gasify the gasoline. At best, only a part of a charge of gasoline can be gasified and if the cylinder is very cold indeed, the charge will not explode at all till the cylinder is warmed up. When preparing to start an engine, first see that the nuts or studs holding cylinder head to cylinder are tight as the heating and cooling of the cylinder are liable to loosen them. Then oil all bearings with a hand oil can and carefully wipe off all outside grease. When all is ready, work the gasoline pump to get the air out of the feed pipes and fill the reservoir. First, the engine must be turned so that the piston is as far back as it will go, and to prevent air being pressed back, the exhaust must be held open, or a cock in priming cup on top of cylinder opened. If gasoline priming is needed, the gasoline must be poured into the priming cup after closing the cock into the cylinder, for it would do no good to merely let the gasoline run down into the cylinder in a cold stream. It must be sprayed in. If the exhaust has been held open, and the priming charge of gasoline is to be drawn in through the regular supply pipe and valve, the exhaust should be closed and the throttle turned on to a point indicated by the manufacturer of the engine. We suppose that the igniter is ready to work. If the hot tube is used, the tube should be hot. If the electric igniter is used, the igniter bar should be in position to be snapped so as to close the circuit and cause a spark when the charge has been compressed. If all is ready, open the cock from which the supply of gasoline is to be obtained, and at the same time turn the engine over so as to draw the charge into the cylinder. If a priming cock has been opened, that must be closed by hand as soon as the cylinder is filled and the piston ready to return for compression. If the regular feed is used, the automatic valve will close of itself. Bring the flywheel over to back center so that piston will compress the charge. With the flywheel in the hand, bring the piston back sharply two or three times, compressing the charge. This repeated compression causes a little heat to be liberated, which warms up the cylinder inside. If the cylinder is very cold, this compression may be repeated until the cylinder is sufficiently warm to ignite. When performing this preparatory compression, the piston may be brought nearly up to the dead center, but not quite. At last, bring it over the dead center, and just as it passes over, snap the electric ignition bar. If an explosion follows, the engine will be started. If the hot tube is used, the flywheel may be brought around sharply each time so that the piston will pass the dead center. As an explosion will follow complete compression. If the explosion does not follow, the flywheel may be turned back again and brought up sharply past the dead center. Each successive compression will warm up the cylinder, till at last an explosion will take place and the engine will be started. More gasoline will be needed to start in cold weather than in warm, and the starting supply should be regulated accordingly. Moreover, when the engine gets to going, the cylinder will warm up, more of the gasoline will vaporize, and a smaller supply will be needed. Then the throttle can be turned so as to reduce the supply. After the engine is started, the water jacket should be set in operation and you should see that the cylinder lubrication is taking place as it ought. As the above method of starting the engine will not always work well, especially in cold weather, what are called self-starters are used. They are variously arranged on different engines, but are constructed on the same general principle. This is, first, to pump air and gasoline into the cylinder, instead of drawing it in by suction. Sometimes the gasoline is forced in by an air compression tank. The engine is turned just past the back center, care having been taken to make sure that the stroke is the regular explosion stroke. This may be told by looking at the valve cam or shaft. If an electric igniter is used, it is set ready to snap by hand. If the tube igniter is used, a detonator is arranged in the cylinder to be charged by the head of a snapping parlor match which can be exploded by hand. Holding the flywheel with one hand, with piston just past back center, fill the compressed end of the cylinder by working the pump or turning on the air in compression tank till you feel a strong pressure on the piston through the flywheel. Then snap igniter or detonator and the engine is off. If throttle valve has not been opened, it may now be immediately opened. The skill comes in managing the flywheel with one hand or one hand and a foot and the igniter, etc. with the other hand. Care must be exercised not to get caught when the flywheel starts off. The foot must never be put through the arm of the wheel, the wheel merely being held when necessary by the ball of the big toe. So that if the flywheel should start suddenly, it would merely slip off the toe without carrying the foot around or unbalancing the engineer. Until one gets used to it, it is better to have someone else manage the flywheel while you look after the gasoline supply, igniter, etc. When used to it, one man can easily start any gasoline engine up to 15 horsepower. What to do with a gasoline engine when it doesn't work? Questions and answers Question If the engine suddenly stops, what would you do? Answer First, see that the gasoline feed is all right Plenty of gasoline in the tank Feed pipe filled Gasoline pump working And then if valves are all in working order Perhaps there may be dirt in the feed reservoir Or the pipe leading from it may be stopped up If everything is right so far Examine the valves to see that they work freely and do not get stuck from lack of good oil or from use of poor oil Raise them a few times to see if they work freely Carefully observe if the air valve is not tight in sleeve of gas valve Question What would be the cause of the piston sticking in the cylinder? Answer Answer. Either it was not properly lubricated, or it got too hot, the heat causing it to expand. Question. Are boxes on a gasoline engine likely to get hot? Answer. Yes, though not so likely as on a steam engine. They must be watched with the same care as they would be on a steam engine. If the engine stops, turn it by hand a few times to see that it works freely without sticking anywhere. Question. Is the electric sparking device likely to get out of order? Answer. Yes. You can always test it by loosening one wire at the cylinder and touching it to the other to see that a spark passes between them. If there is no spark, there is trouble with the battery. Question. How should the batteries be connected up? Answer. A wire should pass from carbon of number one to copper of number two. From carbon of number two to copper of number three, etc. Always from copper to carbon. Never from carbon to carbon or copper to copper. Wire from last carbon to spark coil, and from coil to switch, and from switch to one of the connections on the engine. Wire from copper of number one to the other connection on the engine. In wiring, always scrape the ends of the wire clean and bright, where the connection is to be made with any other metal. Question. What precautions can be taken to keep batteries in order? Answer. The connections between the cells can be changed every few days. Number one being connected with number three. Number three with number five, etc. Alternating them, but always making a single line of connection from one connection on cylinder to first copper from the carbon of that cell to copper of next cell and so on till the circuit to the cylinder is completed When the engine is not in operation always throw out the switch to prevent possible short-circuiting If battery is feeble at first, fasten wires together for half an hour at engine till current gets well started. Question. Is there likely to be trouble with the igniter inside cylinder? Answer. There may be. You will probably find a plug that can be taken out so as to provide a peephole. Never put your eye near this hole, for some gasoline may escape, and when spark is made, it will explode and put out your eye. Always keep the eye a foot away from the hole. Practice looking at the spark when you know it is all right and no gasoline is near, in order that you may get the right position at which to see the spark in case of trouble In any case always take pains to force out any possible gas before snapping igniter to see if the spark works all right. Question. If there is no spark, what should be done? Answer. Clean the platinum points. This may be done by throwing out switch and cutting a piece of pine one-eighth of an inch thick and one-half inch wide, and rubbing it between the points. It may be necessary to push Cam out a trifle to compensate for wear. Question How can you look into peephole without endangering eyesight? Answer By use of a mirror Question. If the hot tube fails to work, what may be done? Answer. Conditions of atmosphere, pressure, etc. vary so much that the length of the tube cannot always be determined. If a tube of the usual length fails to work, try one a little longer or shorter, but not varying over one and one-half inches. Question. When gas is used, what may interfere with gas supply? Answer. Water in the gas pipes. This is always true of gas pipes not properly drained, especially in cold weather when condensation may take place. If water accumulates, tubes must be taken apart and blown out, and if necessary a drain cock can be put in at the lowest point. Question What trouble is likely to be had with the valves? Answer In time, the seats will wear and must be taken out and ground with flour or emery. Question Should the cylinder of a gasoline engine be kept as cool as it can be kept with running water? Answer No It should be as hot as the hand can be borne upon it, or about 100 degrees. If it is kept cooler than this, the gasoline will not gasify well. If a tank is used, the circulation in the tank will justify the temperature properly. The water may be kept at 175 degrees of temperature and used for hot water heating. The exhaust gases are also hot and may be used for heating by carrying in pipes coiled in a hot water heater. Question. Are water joints likely to leak? Answer. Yes. The great heating given the cylinder is liable to loosen the water joints. They are best packed with asbestos soaked in oil, sheets 1 16th inch thick. Old packing should always be thoroughly cleaned off when new packing is put in. Question How may the bearings be readjusted when worn? Answer Usually there are liners to adjust bearing. In crank box, adjust as in steam engine by tightening the key. Question If you hear a loud explosion in the exhaust pipe after the regular explosion, should you be alarmed? Answer No All gas or gasoline engines give them at times and they are harmless. If the gas or gasoline fed to the engine is not sufficient to make an explosive mixture, the engine will perhaps miss the explosion, and live gas will go into the exhaust pipe. After two or three of these have accumulated, an explosion may take place, and the burned gases coming out of the port as hot flames will explode the live gas previously exhausted. Any missing of the regular explosion by the engine, through trouble with battery or the like, will cause the same condition. Question When you get exhaust pipe explosions, what should you do? Answer Turn on the fuel till the exhaust is smoky. Then you know you have fuel enough and more than enough. If the explosions still continue, conclude that the igniter spark is too weak or does not take place. Question What precaution must be taken in cold weather? Answer The water must be carefully drained out of jacket. Question Will common steam engine cylinder oil do for a gasoline engine? Answer No The heat is so great that only a special high-grade mineral oil will do. Any oil containing animal fat will be worse than useless. Question How can you tell if right amount of gas or gasoline is being fed to engine to give highest power? Answer Turn on as much as possible without producing smoke. A smokeless mixture is better than one which causes smoke. Question If you have reason to suppose gas may be in the cylinder, should you try to start cylinder? Answer No Empty the gas all out by turning the engine over a few times by hand, holding exhaust open if necessary. Question How long will a battery run without recharging? Answer The time varies, usually not over three or four months. Question Is it objectionable to connect an electric bell with an engine battery? Answer Certainly Never do it. Question If your engine doesn't run, how many things are unlikely to be the trouble? Answer not more than four. Compression, spark, gas supply, valves. Chapter 14. How to Run a Threshing Machine A threshing machine, though large, is a comparatively simple machine, consisting of a cylinder with teeth working into other teeth, which are usually concaved. This primary part really separates the grain from the husk, and rotary fan and sieves to separate grain from chaff, and some sort of stacker to carry off the straw. The common stacker merely carries off the straw by some endless arrangement of slats working in a long box, while the so-called wind stacker is a pneumatic device for blowing the straw through a large pipe. It has the advantage of keeping the straw under more perfect control than the common stacker. This separation of the grain from the straw is variously affected by different manufacturers, there being three general types, called apron, vibrating, and agitating. The following list of parts packed inside the J.I. Case separator of the agitative type, when it is shipped, will be useful for reference in connection with any type of separator. Two hopper arms, right and left. One hopper bottom. One hopper rod with thumb nut. Two feed tables. Two feed table legs. Two band cutter stands and bolts. One large crankshaft. One grain auger with 1223T pulley and 1154T box. One tailings auger. 1 elevator spout 1 elevator shake arm complete 1 set fishbacks for straw rack 1 elevator pulley 529T 1 beater pulley 6-inch 1254T or 4-inch 1255T 1 elevator drive pulley 1673T 1 crank pulley to drive grain auger 1605T 1 cylinder pulley to drive crank 4 inch 973T or 6 inch 1085T 1 cylinder pulley to drive fan 1347T 1-3-4-8-T or 1-6-3-3-T 1-Fan Pulley 1-2-4-4-T or 1-2-3-1-T 1-Belt Tightener Complete with Pulley 1-Belt Reel 5-0-1-6-T or 1-6-4-2-T with Crank and Bolt 4 shoe sieves 4 shoe rods with nuts and washers 1 conveyor extension 1 sheet iron tailboard 2 tailboard castings 1654T and 1655T In addition to these are the parts of the stacker. As each manufacturer furnishes all needed directions for putting the parts together, we will suppose the separator is in working condition. A new machine should be set up and run for a couple of hours before attempting to thresh any grain. The oil boxes should be carefully cleaned, and all dirt, cinders, and paint removed from the oil holes. The grease cups on cylinder, beater, and crank boxes should be screwed down after being filled with hard oil, moderately thin oil being used for other parts of the machine. Before putting on the belts, turn the machine by hand a few times to see that no parts are loose. Look into the machine on straw rack and conveyor. First connect up belt with engine and run the cylinder only for a time Screw down the grease cup lugs when necessary and see that no box is heat Take off the tightener pulley Clean out oil chambers and thoroughly oil the spindle Then oil each separate bearing in turn, seeing that oil hole is clean and that pulley or journal works freely. The successive belts may then be put on one at a time until the stacker belt is put on after its pulleys have been oiled. Especially note which belts are to run crossed, usually the main belt and the stacker belt You can tell by noting which way the machinery must run to keep the straw moving in the proper direction Oiling on the first run of a machine is especially important, as the bearings are a trifle rough and more liable to heat than after machine has been used for some time. It is well to oil a shaft while it runs, since the motion helps the oil to work in over the whole surface. The sieves, concaves, checkboard, and blinds must be adjusted to the kind of grain to be threshed. When they have been so adjusted, the machine is ready to thresh. Setting Separator It is important that the machine be kept perfectly steady, and that it be level from side to side, though its being a little higher or lower at one end or the other may not matter much. If the level sidewise is not perfect, the grain will have a tendency to work over to one side. A spirit level should be used. One or more of the wheel should be set in holes according to the unevenness of the ground and the rear wheel should be well blocked Get the holes ready judging as well as possible what will give a true level and a convenient position Pull the machine into position and see that it is alright before uncoupling the engine If holes need re-digging to secure proper level, machine may be pulled out and backed in again by the engine When machine is high in front, it can easily be leveled when engine or team have been removed By cramping the front wheels and digging in front of one and behind the other, then pulling the tongue around square Block the right hind wheel to prevent the belt drawing machine forward Always carry a suitable block to have one handy In starting out of holes or on soft ground Cramp the front axle around And it will require only half the power to start That would be required by a straight pull In setting the machine if the position can be chosen. Choose one in which the straw will move in the general direction of the wind, but a little quartering, so that dust and smoke from engine will be carried away from the men and the straw stack. In this position, there is less danger from fire when wood is used. The Cylinder The cylinder is arranged with several rows of teeth working into stationary teeth in what is called the concave It is important that all these teeth be kept tight and that the cylinder should not work from side to side The teeth are liable to get loose in a new machine and should be tightened up frequently A little brine on each nut will cause it to rust slightly and help to hold it in place. If the cylinder slips endwise even a sixteenth of an inch, the teeth will be so much nearer the concaves on one side and so much farther away from them on the other side. Where they are close, they will crack the grain. Where they are wide apart, they will let the straw go through without threshing or taking out the grain. So it is important that the cylinder and its teeth run true and steady. If the teeth get bent in any way, they must be straightened. The speed of the cylinder is important, since its pulley gives motion to the other parts of the machine, and this movement must be up to a certain point to do the work well. A usual speed for the cylinder pulley is 1,075 revolutions per minute, up to 1,150. There is always an arrangement for adjusting the cylinder end-wise so that teeth will come in the middle. This should be adjusted carefully when necessary. The end play to avoid heating may be about 1 64th of an inch. It may be remembered that the cylinder teeth carry the straw to the concaves and the concaves do the threshing. The Concaves The concaves are to be adjusted to suit the kind of grain threshed. When desiring to adjust concaves, lift them up a few times and drop so as to jar out dust. Wedging a block of wood between cylinder teeth and concaves will, in some types of separator, serve to bring up concaves when cylinder is slowly turned by hand. There are from two to six rows of teeth in the concave, and usually the number of rows is adjustable or variable. Two rows will thresh oats, where six are required for flax and timothy. Four rows are commonly used for wheat and barley. The arrangement of rows of teeth and blanks is important. When four rows are used, one is commonly placed well back, one front, blank in the middle. When straw is dry and brittle, cylinder can be given draw by placing blank in front. Always use as few teeth and leave them as low as possible to thresh clean, since with more teeth than necessary, set higher than required, the straw will be cut up and a great deal of chopped straw will get into the sieves, all of which also requires additional power. Sometimes the teeth can be taken out of one row, so that one, three, or five rows may be used. For a specially difficult grain like turkey wheat, a concave with corrugated teeth may be used in sets of three rows each up to nine rows. The corrugated teeth are used for alfalfa in localities where much is raised. The beater and checkboard After the cylinder has loosened the grain from the husk and straw, it must still be separated. Some threshers have a grate under the cylinder and behind it. In any case, the beater causes the heavy grain to work toward the bottom, and the checkboard keeps the grain from being carried to rear on top of the straw, where it would not have a chance to become separated. If the grain is very heavy or damp, there may be a tendency for the straw to stick to the cylinder and be carried around too far. In such a case, the beater should be adjusted to give more space and the checkboard raised to allow the straw to pass to the rear freely. Straw Rack The straw rack and conveyor carry the straw and grain to the rear with a vibratory movement, causing the grain to be shaken out. To do good work, the straw rack must move with a sufficient number of vibrations per minute, say 230. A speed indicator on the crankshaft will show the number of vibrations best. Great care must be taken with this part of the thresher Or a great deal of grain will be carried into the straw The less the straw is cut up, the better this portion of the machine works So the smallest practicable number of teeth in the concave should be used The crank boxes and pit mans should be adjusted so that there is no pounding If the rear vibrating arms drop too low, they get below the dead center and are liable to break, at any rate causing severe pounding and hard running. To prevent this, the crank boxes can be moved forward by putting leather between them and the posts or should be otherwise adjusted, the trouble being due to the pitmans having worn short. The pitmans may be lengthened in some way By putting pieces of leather over the end or the like Or new pitmans may be introduced The fan The chief difficulty likely to arise with the fan is blowing over grain To prevent this, blinds are usually arranged Which may be adjusted while the machine is running so as to prevent the grain from being blown over. At the same time, it is important to clean the grain so the adjustment should not go to one extreme or the other. In windy weather, the blind should be closed more on one side than on the other. The speed of the fan must be adjusted to the requirements of the locality. As much blast should be used as the grain will stand, and heavy feeding requires more wind than light feeding, since the chaff checks the blast to a certain extent. Care should be taken that the wind bored over the grain auger does not get bent, and it should be adjusted, so that the strongest part of the blast will come about the middle of the sieve. Sieves. There is usually one conveyor sieve, which causes the grain to move along, and shoe sieves, which are required to clean the grain thoroughly. Different kinds of sieves are provided for different kinds of grain, and the proper selection and adjustment of these sieves as to mesh, etc., is of the utmost importance. Much depends on the way the sieves are set And on the rate at which the thresher is fed Or the amount of work it is really doing The best guide is close observation and experience Both your own and that of other threshermen And with that I think we'll end this evening's reading From Farm Engines and How to Run Them The Young Engineer's Guide Reading this reminds me of the manual for the Model T and how it seems like a miracle that anything got done by these early machines I hope you enjoyed that If you'd like to read this work for yourself and see the many illustrations it contains As always, you'll find a link to a free e-book from Project Gutenberg in the show description. If you'd like to connect, suggest a boring book you'd like to hear read, or request more from one we've already started, you can drop me an email via our website, www.boringbookspod.com. It's always a pleasure to hear from you. Thank you so much for joining me for this evening's reading Until our next boring book, goodnight